Japanese Non-examined Patent Publication No. 11-232986 discloses an electromagnetic switching device having an electromagnetic device and a contact device in a case.
The electromagnetic switching device comprises an electromagnetic device in which a movable core comes into contact with or separates from a fixed core in response to energization of an excitation coil wound around a coil bobbin, a contact device with a fixed contact and a movable contact which comes into contact with or separates from the fixed contact in conjunction with the movement of the movable core of the electromagnetic device, and a boxy case for housing the electromagnetic device and the contact device. The movable contact is supported by a movable armature, and the armature is connected to the movable core through a movable shaft.
In this electromagnetic switching device, when the excitation coil is energized, the movable core moves to the fixed core side, and the movable shaft and the movable armature move in conjunction with the movement of the movable core, and as a result, the movable contact comes into contact with the fixed contact. When the energization of the excitation coil is stopped, the movable core separates from the fixed core by a spring force of a return spring provided between the fixed core and the movable core, so that the movable contact separates from the fixed contact.
By the way, in the above electromagnetic switching device, when the movable core makes contact with the fixed core, a vibration (or, an impact) occurs. If the vibration is transmitted to the case, the case itself also vibrates, so, for example, the case may come in contact with some part, and a noise may emanate.